Folding knife



FIG. 1 is a front view in elevation of a folding knife illustrated in open position, showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof;

FIG. 7 is an alternate front elevational view of the folding knife illustrated in FIG. 1, shown in folded position; and,

FIG. 8 is a perspective view of the folding knife illustrated in FIG. 1. 

The ornamental design for a folding knife, as shown and described. 